Method of and apparatus for drying sheets in multicolor intaglio printing



July 12, 1932. A, "EGLl I 1,867,256

METHOD OF AND APPARATUS FOR DRYING SHEETS IN MULTICOLOR INTAGLIOPRINTINGv Original Filed May 18, 1929 Fig.5

lowed again by a cold air re resented in side Patented July 12, 1932UNITED STATES PA'TENT OFFICE ARNOLD EGLI, OF HAMBURG, GERMANY METHOD OFAND APPARATUS FOR DRYING SHEETS IN MULTICOLOR IN'IAGLIO PRINTINGApplication filed May 18, 1929, Serial No. 364,268, and in Germany May19,

1928. Renewed November peated taking 1n of color; besides the driedsheet would seldom be in a suitable condition for a further applicationof color.

The present invention provides a novel method and apparatus for thequick drying of the imprinted color wherein the paper is notdisadvantageously influenced.

In accordance with said invention warm air is blown upon the printedsheet after each color printing operation the warm air being dried incertain cases. old air is then blown upon this sheet, the air beingmoistene when required. The application of the last color ispreferably-followed by a warm air treatment for some considerable timefoltreatment on the receiving table.

This heated air is blown against the freshly printed sheets inaccordance with the invention, especially when the back of said sheetsis placed against a surface which is a good conductor of heat; saidsurface being coole when required.

The drawing shows diagrammatically an method, wherein Fig. 1 representsthe general arrangement and Figs. 2-4 the top plan views of detailselevation in Fig. 1,'

i 2 showing a top view of a warm air blasting device,

Fig. 3 being a plan view of the cold air blasting device and Fig. 4 atop view of the warm air supply for the completely printed sheets- Fig.5 shows a section through the shaft of the impression cylinder and thefeed and d sufiicient to dry drain pipes of the cooling means leading toand coming from the cooling chambers of the impression cylinder.

The sheets 4 to be printed are conveyed to the crown of the impressioncylinder, where they are caught by the claws 2 associated with theimpression fields 2. With each revolution of the impression cylinder 1one color is impressed upon a sheet through a printing cylinder 3, afterwhich the freshly printed sheet must be dried before the sheet isprinted by a second printing cylinder.

The drying during the rotation of the impression cylinder is effected asthe latter revolves by causing the sheet to pass an air blower box 5which is supplied with compressed air by a compressed air pipe 5 andequipped with a great number of air nozzles directed towards theimpression cylinder and marked by little arrows in the drawingindicating the discharge of air. I

The box 5 is divided into a number of separate chambers k, 70, arrangedin the direction of the impression cylinder shaft as will be seen fromFig. 2.

Electric heating elements 6 arranged in the chambers k, k" aresuppliedby the current generator 20 and are regulated separately at 21.

The warm air is blown thus through the openings 5" upon the printedsheet when the latter is passing the heating arrangement 5 and thechambers in, k" thereof and this blowing action the applied color.

Provision is also made for the dividing up of the space in the heatingapparatus 5 I arrangement for carrying out my improved into chambers andthe regulating of the heating in the several chambers so that moreintensified heating and drying on such places of the sheet to which thecolors are applied more thickly is accomplished. The ,air supply of theseveral chambers of the drying arrangement 5, 6 may also be regulated byway of throttling devies 22. The air can be dried by conveying the samethrough the drier 23, or it can be conveyed to the heating elements 5without being dried by closing the valve 24 and opening of the valve 25.

In consequence of the fact that the back of short duration will be 5 agood conductor of heat, prevents local heating, the temperature of thesheet is not changed except at thesurface exposed immediately to the hotair flow. There are, however, printing colors which take an exceedinglylong time to dry, necessitating the employment of a s'tronglyheated aircurrent in order to attain a suflicient drying of the print mg colorduring the short time intervals the printed sheet is passing through thehot air current. To keep the temperature of the sheet constant also insuch a case the cooling effect of the impression cylinder is increased.According to the present invention, this is accomplisheflhrough thearrangement of cooling chambe 34 in the impression cylinder, whereinthee oling chambers 34 are connected to each other by way of pipe lines,35, the last cooling chambers being directly connected with the supplyand discharge line of the cooling means. For this purpose, as is shownin Fig. 5, the shaft 36 of the impression cylinder 1 is provided withbores 37 and 38. Rings 41 and 42 slide in grooves 39 and in theshaft 36,said rings having hollow spaces 43 and 44, which on one side arecontinuously connected with the bore holes 38 and 37 of the shaft, onthe other side with a supply pipe 46 and with a discharge pipe 47,respectively, for the cooling means. The slip rings are divided at '48and 49 to allow the mounting of same on the shaft grooves. They arerigidly supported in the engine frame at 50. Rings 51 and 52 are shrunkat a suitable place upon the shaft 36, said rings revolving with theshaft in contradistinction to the stationary rings 41 and 42, and areconnected with the last cooling chambers 34"by way of the lines 53 and 54. Cooling water, is supplied to the stationary pipe line 46, thiscooling water flowing constantly through the ring shaped hollow space 43into the hole 38 whence it flows by way of pipe line 54 into one of thelast cooling chambers 34'.. The cool ing means, after flowing throughall the chambers 34 and 34 by way of the pipe connections 35, is drainedfrom the other chamber 34 by way of pipe line 53 into the stationarycooling means discharge line 47 through the hole 37 and the hollow space44.

The sheet, after passing the device 5 and before passing the printingcylinder to get a new color impression, passes a blower device 7 whichdirects a strongblast of cold air and, when desired, of moistened airagainst said sheet. The vapors produced by the heated air are in thismanner blown away. The cold air current rests the sheet into the stateit was in before the first print. The sheet may also be slightlymoistened by such cold blast insures that the sheet arrives conveyingcooling air,

table until another sheet arrives. By these.

ness of the sheet would cause a deficient a sorption of color.

This second air treatment, together with the cooling effect of theimpression cylinder,

in a suitable condition at each impression operation with the printingcylinders 3.

The sheets which have received their last imprint, must-be dried alittle more, than after the previous impressions because the thirdcolorthe blue color-requires the most time to dry. The sheet istherefore caught after passing the hot air openings 5 three times, bythe claws 8 of the revolving crossed arms 9 for leading it to thedelivery table 10.

'On its way to the table 10 the printing side of the sheet passes thepipes 11 coming from the upper ends of the device5, or of the chambersis, k and is thus swept by heated compressed air. This warm air forcesthe back of the sheet against a sheet metal cover 12 in such a way thatthe back side is kept relatively cool. To insure this cooling eflect ofthe cover 12, a pipe 13 may be employed to dischargea cooling ,means,for instance water upon said cover. In this way the same result isaccomplished as with the metallic shell of the impression cylinder 1,namely that the drying eifectis limited to the surface of the treatedsheet. By these means the gaseous oils of the printed color are removed;as the heat transmission from the printed side of the sheet to the coldface supporting it is much larger than the heat'supplied by way of thewarm air, an undesirable drying of the paper need not be feared.

- The sheet, completely printed and dried on its surface, is then blownthrough pipes '14, against the delivery means the sheet returns to itsinitial state of dryness.

In the embodiment of the invention illustrated the cooling arrangements7 and 14 receive their cold air by way of a cooling apparatus 17 from apipe 18, moistened air being added through a feed line 19 by means ofthe spray 26. In the same way, by means of pipes 15 and 16, connectedwith the cold air line 27 and provided .With suitable delivery nozzles28 and 29, the sheet between the printing cylinders is blown against theimpression cylinder 1. The warm air pipe 5 receives its air from theblower 30, and the cold air pipe 27 its cold air from the blower 31, athrottling device 32 in the pipe 19 for moist air permitting theregulation of the addition of moist air to the cold air. The cool ingapparatus 17 receives its cooling liquid, such as cooling water, byway'of pipe 33.

I claim:

1. In a multi-color sheet intaglio printing machine, in combination, animpression cylinder, printing cylinders, movable towards the impressioncylinder and away from it, means adapted to-convey different printingcolors to the printing cylinders, boxes arranged around the impressioncylinder and subdivided 1n the direction of the shaft of the impressioncylinder, means for supplying the several boxes with compressed air,means for regulating the compressed air supply of the several boxes,said boxes constructed with discharge nozzles on the sides facing theimpression cylinder, heating arrangements for heating the air dischargeby the individual boxes, and means for changing the degree of heating ofsuch air.

2. The improvement in the art of drying rinted sheets in multi-colorintaglio printing, which comprises directing a stream of heated air onthe printed surface of a sheet while simultan usly holding the rear faceof such sheet agai st a cooled surfaceto keep the body of such sheetcool.

3. The improvement in the art of drying printed sheets in multi-colorintaglio printing, which comprises directing a stream of heated driedair upon the printed surface of a sheet while simultaneously holding therear face of such sheet against a cooled surface to keep the body ofsuch sheet cool.

4. The improvement in the art of drying printed sheets in multi-colorintaglio printing, which comprises directing a stream of heated air uponthe printed surface of a sheet while simultaneously holding the rearfaceof such sheet against a cooled surface to keep the body of such sheetcool, and directing a stream of cold air upon the printed surface ofsaid sheet before applying the next color thereon.

5. The improvement in the art of drying printed sheets in multi-colorintaglio printing, which comprises directing a stream of heated air uponthe printed surface of a sheet while simultaneously holding the rearface of such sheet against a cooledsurface to keep the body of suchsheet cool, and directing a stream of cold moist air upon the printedsurface of said sheet before applying the next color thereon.

6. The improvement in the art of dryingprinted sheets in multi-colorintaglio printing,vwhich comprises directing a stream of heated'air uponthe printed surface of a sheet while simultaneously holding the rearface of such sheet against a cooled surface to keep the body of suchsheet cool, directing a stream of cold air upon the printed surface ofsaid sheet before applying the next color thereon, and blowing heatedair against the printed surface of the sheet after the application ofthe last color, while simultaneously holding Ehe rear face of the sheetagainst a cool surace.

7. The improvement in the art of drying printed sheets in multi-colorintaglio printing, which comprises directing a stream of heated air uponthe printed surface of a sheet while simultaneously holding the rearface of such sheet against a cooled surface to keep the body of suchsheet cool, directing a stream of cold air upon the printed surface ofsaid sheet before applying the next color thereon, blowing heated airagainst the printed surface of the sheet after the application of thelast color, while simultaneously holding the rear face of the sheetagainst a cool surface, depositing the completely printed sheet anddirecting a stream of cold air thereupon.

8. The improvement in the art of drying printed sheets in multi-colorintaglio print ing, which comprises directing a stream 0 heated air uponthe printed surface of a sheet while simultaneously holding the rearface of such sheet against a cooled surface to keep the body of suchsheet cool, directing a stream of cold air upon the printed surface of'said sheet before applying the next color thereon, blowing heated airagainst the printed'surface of the sheet after the application of thelast color, while simultaneously holding the rear face of the sheetagainst a cool surface, depositing the completely printed sheet anddirecting a stream of cold moist air thereupon.

9. In a multi-color intaglio printing machine, in combination, animpression cylin der, a plurality of printing cylinders movable towardand away from the impression cylinder, means for cooling the surfaceupon which a sheet to be printed rests, and means for directing a streamof heated air upon the printed surface of such sheet.

10. The combination as set forth in claim 9, including means for dryingsaid heated air.

11. In a multi-colo'r intaglio printing ma chine, in combination, animpression cylinder, a plurality of printing cylinders movable towardand away from the impression cylinder, means for cooling the surfaceupon which a sheet to be printed rests, means for directing a stream "ofheated air upon'the printed surface of such sheet, and means fordirecting a stream'of cold air upon a printed sheet prior to theapplication "of the next color. I

12. The combination as set forth in claim 11, including means formoistening the stream of cold air. j

13. In a multi-color intaglio printing machine, in combination, animpression cylinder, a plurality of printing cylinders movable towardand away from the impression cylinder, means for cooling the surfaceupon which a sheet to be printed rests, means for directing a stream ofheated air upon the printed surface of such sheet, gripping mechanismarranged to strip the printed sheet from the impression cylinder andincluding a plurality of gripping.- arms,'-a cover concentric with thepath of movement of said gripping arms, conduits arranged between,

said arms, means for feeding heated air to said conduits, nozzles at theoutlet ends of said conduits for discharging the heated air' 5 againstthe printed surface of the sheet, and means for cooling said cover.

14. In a multi-colorintaglio printing machine, in combination, animpression cylinder, aplurality of printing cylinders movm able towardand away from the impression cylinder, ineans for cooling the surfaceupon which a sheet to be printed rests, means for directing a stream ofheated air upon the printed surface of such sheet, gripping mechanismarranged to strip the printed sheet from the impression cylinder andincluding a plurality of gripping arms, a cover concentric with the pathof movement of said gripping arms, conduitsarranged between said arms,means for feeding heated air to said conduits, nozzles at the outletends of said conduits for discharging the heated air against the printedsurface of the sheet, means for cooling said cover, a delivery table,

conduits arranged above said table, means for conducting cold air tosaid conduits, and nozzles at the outlet ends of said conduits fordirecting such cold air against a freshly deposited sheet,

80 ARNOLD EGLI.

